Yeah they sell frozen mice at our petsmart. They don't provide the best care to their reptiles but I'd say most places do a decent job of holding the most popular reptile species for a few weeks while they get homed. Most aren't entirely ignorant. In fact I'd say the majority (not all) of pet stores have that one "reptile dude" who's been working there for like 10 years and actually knows how to care for the animals.

The moron teenagers everyone runs into are literally there to open the cage and box up the animal. That's it. Those people aren't responsible for the actual care of the animal. They give terrible care advice but to be honest even if someone gives a total noob amazing world class advice their animal will probably still die because they didn't research the dang thing in the first place. If the customer doesn't care enough to read up on their new pet they probably won't care about their new pet after its not "new" anymore.